Window units for oven doors conventionally have consisted of constructions in which the space between the glass panes is sealed to prevent oven vapors from penetrating that space and subsequently condensing on the glass surfaces. Such constructions result in the outer surface of the outer glass pane reaching fairly high temperatures. Various attempts have been made to reduce the temperature of the outer pane by providing for the flow of air by convection over the inner surface of the outer pane. Such proposals have involved constructions that could not utilize a self-contained window unit adapted for easy installation into the oven doors of the various manufacturers. Previous constructions sometimes have employed an outer glass pane mounted on the front door panel rather than forming a part of a self-contained unit. That is more expensive and often requires a mounting clip or clips welded to the front door panel. A weld of this kind can show through and be unsightly.
The present invention provides a self-contained three-pane window unit in which the front or outer glass is a part of the unit. Moreover, the self-contained window unit of the present invention permits a maximum air flow and minimum thermal conduction. It can be utilized in present door assemblies having air flow cooling means without additional tooling.
The self-contained window unit of the present invention is designed to permit easy removal of the front glass pane for cleaning the air passage through the window unit.
The window unit of the present invention has a sealed two-pane package that minimizes heat radiation to the air passage.
The three-pane self-contained window unit can be manufactured at low cost by eliminating material waste and expensive tooling otherwise required to produce air wash slots. Since the unit is self-contained, range manufacturers need not concern themselves with washing and mounting individual pieces of glass to the front and rear door panels.
Further advantages of the present invention include the provision of easy removal of the front glass pane by an upward sliding movement to facilitae cleaning of the air passage. This is accomplished in the present instance by the construction of mounting clips particularly along the top of the assembly which permit the front pane to be pressed outwardly clear of the top clips and then to be removed by upward sliding.